Heaters on trains

[windows_boy]

Hi all,

Here's a random question for you! I travel to work daily from Lowestoft to Norwich. Can someone explain to me why the heaters on the old sprinters often seem to be on in the summer and off in the winter? I don't get it! Its not causing me any discomfort, but I always wonder why that is? Its only a trivial thing, so I never wanted to bother the conducter about it.

(PS.... stumbled across this forum looking for info on NXEA strike, but now I'm here, I thought I might ask this question).

 

[O L Leigh]

Here's a random question for you! I travel to work daily from Lowestoft to Norwich. Can someone explain to me why the heaters on the old sprinters often seem to be on in the summer and off in the winter? I don't get it! Its not causing me any discomfort, but I always wonder why that is? Its only a trivial thing, so I never wanted to bother the conducter about it.

I don't know specific details about Sprinters, but I have to check that you're certain it's the heating. It's just that I get complaints from punters about the heating being on when it isn't. The cause is just that the ambient air temperature is high so that you get very little cooling effect from having the window vents open because the air coming through is hot. If it really is the heaters you should be able to feel it at ankle height, as the heaters are generally at floor level.

The problem with a lot of BR-era train heating is that it is set to the same level all year round and cannot be adjusted. Our electric units have two settings that are controlled by a thermostat; high and low. The low setting is just to maintain the temperature while the high setting is there to actually heat the train up. The problem with this single level is that it is often too much in the summer (even on low) and not quite enough in the winter. However, if the thermostat was faulty it would make the carriage unbearably hot in the summer and unbearably cold in the winter. Having experienced both extremes I can say with some confidence that you would know for sure whether or not your train was suffering from faulty heating. However, if it is then you should bring it to the attention of the traincrew so that it can be reported as a fault.

There is a potential issue that can confuse matters further, and that is the location of the thermostats. We have a particular problem with our Cl317/7's. These units have been fitted with A/C and it works really well at controlling the internal temperature provided that the window vents are kept closed. Because the thermostats are located inside the ceiling panels, problems arise when folk start opening the vents for fresh air. What happens is that the air coming in from outside sets up a breeze of cool air at ceiling height which cools the thermostats. Sensing the drop in temperature, these switch the A/C off and the heating on which makes the internal temperature at passenger level rise. The punters get hot and open more and more vents in an attempt to compensate, which in turn does nothing to switch the heating off again. We get to the other end and I then get a lot of earache because the train is boiling hot. It's a never ending fight to keep the doors and windows closed long enough for the system to correct itself.

O L Leigh

 

[driver9000]

Pacer and Sprinter series trains have their heating supplied by waste engine heat by passing the coolant around the heating system for the saloons, this is 'topped up' by an Auxiliary (webasto) heater which burns diesel to supply heat and also a pre-heater for the engine in cold weather. The system is set to maintain a constant temperature - 20c if I recall rightly - and on Sprinters there is nothing to allow the crew to switch it off except for tripping the fans mcb which is frowned on
--- old post above --- --- new post below ---
Class 156 trains have a heating outlet about half way down the saloon between the seatbacks where 150s have a couple of box heaters dotted about the saloon. Both are Sprinter trains, and both systems cant be altered by the crew - Ive searched all the lockers I can and have never found the thermostat

 

[windows_boy]

Got to say I'm not complaining at all. Just interested is all. When I was a kid I loved trains and always wanted to know how they worked (I guess I still do.... and I'm pushing 40 now!).

The reason I think the heating may be on is that there's heat coming from the ducts along the floor on either side of carriage, I had assumed the heaters were on for some reason, maybe to help keep the engine coolant temperature down on warm days. Conversely, in winter sometimes there's heat coming from the ducts and sometimes there isn't.

 

[markem41]

Do Pacers have heat running along and through the tubular grab rails near the doors? They always seem extremely hot when you hold on to them - like heated towel rails!

 

[driver9000]

markem41 - yes the former FNW 142 that retain their roof pod heaters have the coolant supply pipe running through a grab rail, it certainly suprises people! the ATN and MerseyRail 142s lost the roof heaters on refurbishment although the pods remain

 

[philjo]

on the GN route 313s it is not unknown to be warmer on the platform outside than on the train in winter, especially when the train comes in tot he station out of the siding with all of the windows open!
Some mornings you can see your breath in front of you inside the train !!

We regularly complained to WAGN then FCC - it is generally better now, but we still had some unheated morings last winter.
it appeared that one set of thermostats was faulty (we suspect thay they were reverse wired to switch the heatin off below a certain temperature, as it often came on during warmer days in spring when it wasn't needed!

 

[TrainBrain185]

markem41 - yes the former FNW 142 that retain their roof pod heaters have the coolant supply pipe running through a grab rail, it certainly suprises people! the ATN and MerseyRail 142s lost the roof heaters on refurbishment although the pods remain

Yes indeed, the original 141/142 Pacer heater arrangement was based on the Leyland National bus with a roof mounted heater system blowing warm air from vents above the saloon windows. This proved both troublesome and ineffective and when heaters needed maintenance, they were full of dust and debris.
It was therefore a great move to install Purmo style heaters at floor level on the North Eastern units.
Another reason why heaters are sometimes left on in summer is that it creates a larger coolant flow area thus reducing the engines running hot and setting off over temperature warnings which sometimes causes them to shut down to prevent engine damage.
Regards:

 

[O L Leigh]

on the GN route 313s it is not unknown to be warmer on the platform outside than on the train in winter, especially when the train comes in tot he station out of the siding with all of the windows open!
Some mornings you can see your breath in front of you inside the train !!

We regularly complained to WAGN then FCC - it is generally better now, but we still had some unheated morings last winter.
it appeared that one set of thermostats was faulty (we suspect thay they were reverse wired to switch the heatin off below a certain temperature, as it often came on during warmer days in spring when it wasn't needed!

This is a particular problem on the first trip, especially in the winter.

I don't know what FCC GN have been doing to their units, but ours had an energy-saving modification to the heating system. Basically there is a time-out after the key has been removed. If a key isn't put in again within a certain timeframe the heating system shuts down. This means that trains stabled overnight are usually unheated and freezing cold when they are brought into service and it takes a trip or two before the internal temperature reaches a comfortable level.

O L Leigh

 

[Bush]

Regarding heating in Sprinter series units, its as Driver 9000 says.

Class 150's - In the saloon, there are mini heat matrix's under every other seat (they are basically like a small radiator) that run off the engine coolant system you do not stop the flow to these heaters as they are part of the engine coolant system. the way the heating works is by way of a thermostat in the saloon (like your household thermostat can be regulated) one of our exam jobs is to ensure they are set to the correct level (about 20c) attached to these heater matrix's are a 24v fan housed within the cowling of the heater. When the ambient temperture drops in the saloon the heater relay will set which of course draws the air in from the saloon across the matrix's and out producing heat, it trips out again when it reaches ambient temperture.
So, the engine coolant operates at a temperature of 78c-86c. So what you have to remember, is that coolant running at this temperature is always running through the matrix's in the saloon whether the fans are cut in or not. Thus why some days when the air is still in the summer, you'd be fooled into thinking the heating is on, it isn't its just the coolant pumping round the system as it should.
On some cold Winters mornings, when the dmu's are coming out of the sidings, you have to remember that the train may of only been run up 15 minutes before hand, thus would be pretty chilly inside! The Engine Coolant temperature will never get up to the ideal operating temperature running at an idle speed in the sidings on a very cold day. To combat this problem we have whats known as the Webasto Heater. If the driver when he gets on and starts his engine remembers to press the Pre Heat button in each cab. The Webasto Heater should prime and then fire up, this as it says pre heats the engine coolant. And it will heat it to its operating temperature. A Good heater that recieves good maintenance should heat up the coolant in 10 - 15mins. Remember though, the saloons still got to heat up. So the carriage warming process should take in the region of about 30 minutes.

If however the driver does not press the pre heat button in the cab, your going to have a pretty chilly carriage for a few hours till the coolant reaches operating temperature, also as the thermostat has detected the saloon temperature is below ambient, the heater fans will kick in, blowing chilly/luke warm air around the saloon.

142's - Like above, but instead of having a heater matrix under every other seat, they have 2 matrix's with 2 fans for each in the pod on the roof. They blow the air through the ducting in the roof into the saloon. A problem with this of course is as the old saying goes "Heat Rises".